The present specification relates to K-nearest neighbor query evaluation, for example, using space transformation.
Location-based services (LBS) use one of many fundamental classes of queries, for example, K-nearest neighbor (KNN), range queries, and the like. In such queries, a group of mobile users want to find the location of their K closest objects from a query point (KNN) or all objects located in a certain area of interest (range). These two types of queries are termed Spatial Queries. Evaluating KNN (range) queries may require that the location of the query point (query window) be known in order to perform the query. This, in turn, may require knowledge of a user's location.